The acronym for “certified electron microscopy technologist” is CEMT, and these letters designate the bearer as having passed the written and practical exams necessary to become “certified”! The acronym was approved by the MSA Council to more firmly provide a professional identification of certification in the area of transmission electron microscopy (TEM) of biological tissue. A CEMT may use these initials after his or her name for as long as the certification remains valid (for example, Jane Doe, AA, BS, CEMT).

Fluorescence is a property of certain fluorophores, which allows them to absorb light at one wavelength and emit the light at another, longer wavelength. This fluorescence can be used as a tool to study the interactions of numerous components within a cell. With the use of fluorescent probes, proteins or other cellular matter can be specifically labeled in a fixed or live cell. This allows scientists to closely monitor microscopic cellular functions in order to gain a greater understanding of living biological processes.

Fluorescence Resonance Energy Transfer (FRET) imaging microscopy is an important and reliable tool for studying minute molecular processes in space and time within a single cell. FRET spectroscopy is a better method for studying the structure and localization of proteins in physiological conditions than are X-ray diffraction, nuclear magnetic resonance, and electron microscopy.

Poly-L-lysine of a medium molecular weight, 30,000 to 70,000 Daltons (Sigma–Aldrich), is currently used in our facility as a polycationic adhesive on 5 mm square silicon chips to secure individual anionic cells and particles for ease of processing and viewing in the scanning electron microscope. In this technique, a solution of 1 mg/ml of poly-L-lysine is dissolved in distilled water. Drops of the solution are placed onto clean 5 mm square silicon chips and allowed to sit for one to several hours before being wicked away. The prepared chips are used immediately. Suspended cells are then applied to the chips and allowed to settle and adhere, after which they are washed and fixed. Alternatively, fixed suspended cells or particles are applied to these silicon chips. The cells and particles secured to the silicon chips are easily handled through processing steps such as dehydration, critical point drying, and metal sputter coating for viewing in the scanning electron microscope. Presented herein is a brief history of the evolution of the technique of using poly-L-lysine as an adhesive for SEM.

Since we do a lot of small-sample critical-point drying (CPD) for SEM, we assemble our own drying capsules which can be manufactured easily in quantity. Materials' cost at current prices is about $10 for 50 capsules. About 25 capsules can be manufactured in an hour. The completed capsule consists of a small polypropylene chamber with fine-mesh, stainless-steel screen caps at each end that allow easy exchange of solvents. shows the steps ofthe assembly process. The base of one capsule is cut off with a razor blade, the cap of a second capsule, for a bottom (Figure 1a). Chamber length can be 5 to 14mm. One-quarter-inch holes are punched through the center of each cap using a paper punch whose spring/detente has been removed to pass the caps' rim (Figure 1b). A sheet-metal shim punch is used to create 3/8" disks of 60-mesh stainless steel wire cloth.

A large part of the preparation of semiconductor samples for SEM and TEM observations involves the creation of cross sections to expose subsurface defects and three-dimensional structure. A powerful new combination of FIB (FEI Company, Hillsboro, Oregon, http://www.feic.com ) with automated microcleaving technology (SELA, Santa Clara, California, http://www. sela.com ) now offers a comprehensive solution for fast, easy and accurate sample preparation.

For people in a small EM lab, keeping stable stain solutions that don't accumulate precipitates over time can be a problem. Over the last 26 years, I have adapted the method originally described by Venable and Coggeshall (1) to address this need

As progress indicators in electron microscopy, advances in spatial resolution and in spectroscopy probably attract most frequent attention. Improved user-friendliness has also been significant even when judged in comparison with scanned probe microscopy. Evidence for developments in in-situ microscopy at least equally impressive can be found by comparing the relevant sections of the book by Hirsch et al. and a more recent compilation.

Peter Hirsch's research group swiftly discovered the power and frustrations of in-situ microscopy. The cine film of dislocation motion observed in the earliest diffraction contrast studies, and attributed to the thermal stresses generated by the electron beam, was extremely effective in convincing the wider community that it was indeed dislocations that were being observed.

A thorough knowledge of structural and chemical properties is essential in the fields of nanotechnology, materials research, and life science, leading to a growing demand for characterization methods for heterogeneous systems on the nanometer scale. However, certain properties are difficult to study with conventional characterization techniques due to either limited resolution or the inability to differentiate materials chemically without inflicting damage or using invasive techniques such as staining. Confocal Raman Imaging can effectively overcome these fundamental obstacles. In Confocal Raman Imaging, the acquisition time for one Raman spectrum is a crucial value, as it determines the acquisition time of the image, which typically consists of tens of thousands of Raman spectra. This article describes how the use of a spectroscopic Electron Multiplying-CCD (EMCCD) as the detector can significantly reduce the acquisition time to a few milliseconds per spectrum, as well as tremendously improve sensitivity.

Thin films in microcircuits can vary from as little a few hundred angstroms, in the case of dielectrics such as silicon nitride and silicon dioxide, to several microns in the case of interconnects. However, most metallization systems used as interconnects and in active structures are generally in the order of 0.5 μm to 4 μm. Gold has a number of desirable properties such as high electrical conductivity, the ability to be easily electroplated, low residual stress after deposition, corrosion resistance etc., Gold is commonly found in microelectronic devices, particularly in high frequency applications like cellular telephony, fiber-optic amplifiers and other high frequency analog applications. An aqueous potassium iodide solution offers a fast and relatively safe method for the removal of thin gold films.

Efforts to understand the basic mechanisms of angiogenesis, that is, the formation of new blood vessels from existing vasculature, have been limited by the methods that are currently used to measure vessel growth. Although in vivo assays provide the best environment in which to track angiogenesis, inherent difficulties in obtaining reproducible data limit the power of this approach. Limitations include: environmental variations between experimental animals, induction of inflammatory responses by surgical methods, and labor-intensive blood vessel quantification procedures. A better assay would measure vessel growth in one animal at multiple time points and would focus on minimization of artifacts induced by experimental manipulation.

In my 20 plus years of experience, I have found that nearly every specimen contaminates to some degree (some slower, some faster) in an electron microscope regardless of the manufacturer. Most of this contamination comes from the specimen, and it's magnitude is a function of the sample (metallic, semiconductor, organic, etc.), the method of preparation (electrochemical chemical, microtoming, ion milling, etc.), the microscope conditions, the probe and probe current - plus a number of less well controlled factors. Reactive gas plasmas can fortunately be used to mitigate the contamination process and frequently reduce the problem to negligible levels. Basically, one places the specimen/stage in a “tow energy plasma” where the gas acts like a catalyst for a localized surface chemical reaction, The energy of the plasma breaks weak bonds of the hydrocarbon compounds on the surface which then make these species somewhat volatile so that they can further react with the gas in the plasma.

In a previous article [1], stereological methods for measuring volume, surface, length, and number were described. The present article will briefly discuss sampling methods, as well as techniques for optimizing the number of animals per group and the number of measurements per animal when planning a morphometric study.

Fluorescence imaging of brains from older animals, particularly primates, can be hindered by the presence of lipofuscin, a strongly fluorescent pigment that accumulates with age, primarily in neuronal cells. Lipofuscin has a broad emission spectrum that overlaps emission of most fluorescent labels, is present throughout the brain and other tissues, and is very hard to quench chemically (Schnella et at.. Journal of Histochemistry and Cytochemistry, Vol. 47, 719-730, 1999). A more convenient way to eliminate lipofuscin from fluorescence images is the use image arithmetic to subtract its signal. This method takes advantage of lipofuscin's broad emission spectrum that makes it appear in all fluorescence channels.

Giovanni Amici was an Italian microscopist, astronomer, optical instrument designer, and botanist who is best known as the achromatic lens inventor. He also designed reflecting telescopes and introduced a lens for the inspection of an objective's rear focal plane, termed the Amici-Bertrand lens. Aditionally, in 1850 he invented the water immersion lens.

Advances in charged couple device (CCD) design, low cast processor power, cheap memory and dropping prices of digital cameras over the last few years have made the CCD digital camera art attractive alternative to the film camera for many imaging applications. This is especially true in macro imaging where it appears likely that digital cameras will replace film cameras (curiously, Long (2001), says otherwise). As will be described here, a digital camera equipped with a quality macro-zoom lens, generates images with a depth of field (e.g., Fig. 1) that greatly surpass images produced by a film camera with a comparable lens system.

The confocal laser-scanning microscope (CLSM) has enormous potential in many biological fields. The reliability of the CLSM to obtain specific measurements and quantify fluorescence data is dependent on using a correctly aligned machine that contains a stable laser power. For many applications it is useful to know the CLSM system's performance prior to acquiring data images so the necessary resolution, sensitivity and precision can be obtained. Applications involving deconvolution, FRET and quantification necessitate that the confocal microscope is correctly configured and operating at the highest performance levels.

Metallic and non-metallic nanoparticles (NPs), ranging in size from 1–200 nm, have unique functional properties that differ from their bulk materials and their component atoms or molecules. These unique properties have driven the demand for nano-sized materials and new methods to synthesize NPs, which are used in drug delivery systems, bio-imaging agents, catalysts, photonics, and optical devices. Inorganic NPs can be synthesized with a variety of methods that impart size, shape, and other structural properties. Cobalt-based NPs, for instance, display unique size and shape-dependent magnetic properties, while the band gap, UV blocking properties and stability of zinc oxide (ZnO) NPs enable new applications in products ranging from cosmetics to solar cell power.